Example F.1-1B W-shape flexural member design in strong-axis bending, continuously braced

The results are generated with SDC Verifier 3.7.1 and calculated with FEMAP v11.0.0

Task:

Verify the available flexural strength of the W18×50, ASTM A992 beam selected in Example F1-1A by applying the requirements of the AISC Specification directly.

Solution:

From AISC Manual Table 2-4, the material properties are as follows:

W18×50

ASTM A992

Fy = 50 ksi

Fu = 65 ksi

From AISC Manual Table 1-1, the geometric properties are as follows

W×50

Zx = 101 in3

Nominal Flexural Strength, Mn

Per the User Note in AISC Specification Section F2, the section is compact. Because the beam is continuously braced and compact, only the yielding limit state applies.

From AISC Specification Section F1, the available flexural strength is:

Example from AISC Design Examples

Material summary

Properties Summary

Geometry Property Value
Height 18.00
Width 7.50
h 18.00
a 7.50
b 7.50
c 0.57
d 0.36
t 0.57

FEM Loads and Constraint

1..Dead load (0.45 kip/ft)

2..Live load (0.75 kip/ft)

Constraint

1..Pinned

Check 1..ANSI / AISC LRFD 360-10

14..Bending

All (IL1, 17 Shapes)

Comparing results of calculation in SDC Verifier and in Example F.1-1B we can see that values completely match.

The available flexural strength is 0.9*412.4 = 371 kip-ft.